Pin-type insulator

ABSTRACT

In a pin-type insulator, one of two channel-shaped conductorgripping elements is sealed to the outermost dielectric element to transmit to that dielectric element, either directly or via a cementitious mass filling a cavity in that dielectric element, at least part of the stress imposed on the gripping elements by the conductor which is supported by the insulator.

United States Patent Willem 14 1 Nov. 21, 1972 [54] PIN-TYPE INSULATOR821,746 5/1906 Richard ..174/ 196 X 843,258 2/1907 Clark ..174/169 X[72] Gusset Frame 2,071,231 2/1937 Jones ..174/169 [73] Assignee:Ceraver, Paris, France 2,135,360 11/1938 Taylor ..174/169 [22] Filed: y21,1971 2,239,792 4/1941 Matthes ..l74/169 X [21] Appl. No.: 145,828Primary Examiner-Laramie E. Askin Attorney-Pennie, Edmonds, Morton,Taylor & Adams [30] Foreign Application Priority Data May 25, 1970France ..7019002 ABSTRACT In a pin-type insulator, one of twochannel-shaped U-S. Cl. conductopg ipping elements is ealed to theouterl74/209 most dielectric element to transmit to that dielectric [51]Int. Cl. 17/16, element either directly or via a cemenfitious mass Field01 Search 5, filling a cavity in that dielectric element, at least part174/177, 178, 180, 194, 195, 196, 209, 210 of the stress imposed on thegripping elements by the conductor which is supported by the insulator.[56] References Cited 4 Cl m 4 graying F g UNITED STATES PATENTS 6,77910/1849 Livingston et al. ....174/169 X PATliNTEnunvzl I972 MmS W NMHHIII w m n 2 m l NN N l MN m\ W m INVENTOR.

Michel Willem ATTORNEYS PIN-TYPE INSULATOR The present inventionpertains to pin-type electric insulators including gripping means tohold the electric conductors intended to be supported by thoseinsulators.

Pin-type insulators have been heretofore proposed including a pluralityof dielectric elements made of glass or porcelain rigidly coupledtogether in coaxial relation, for example by means of a cement, with oneof the elements affixed to a pin by means of which the insulator ismounted horizontally or vertically on a pole or tower. These insulatorssupport an electric conductor by means of one or more metallic elementswhich in turn are usually fixed to a metallic stem sealed or cemented tothe uppermost or outermost dielectric element, farthest from thesupporting pin.

A shortcoming of this manner of holding the conductor is that the entireweight thereof is borne by the metallic element which contacts it, sothat it is necessary to use a supporting stem having high mechanicalstrength. This requires a large cross-section for the stem and aconsequent increased size for the insulator.

The invention proposes to surmount this shortcoming by providing aninsulator of the type hereinabove described in which the weight of theconductor is not carried in its entirety by the stern engaged by theconductor, but is rather transmitted at least in part to the cement bywhich that stem is sealed into the outermost dielectric element. Theinvention also provides means for fastening the conductor to theinsulator which are simple, easy to assemble and disassemble, and whichfacilitate replacement of the insulator in the event of its accidentalbreakage.

In accordance with the invention, the outermost dielectric elementsustains the conductor by means of gripping elements which comprise twoconcave channel-shaped pieces surrounding the conductor, one of thesebeing fixed to the outermost dielectric element, whereas the other oneis movable and can be tightened into a position to hold the conductorwith the aid of fastening means provided on thatoutermost dielectricelement.

The means for tightening the two channel-shaped pieces against theconductor may comprise for example a nut threaded onto a threaded stemwhich is cemented to the outermost dielectric element, this stem passingthrough openings in the channel-shaped pieces in such fashion thattightening of the nut on its stem moves the movable one ofthose piecesso as to stress it against the stationary one.

The nut may advantageously include a ring or bridle so as to besusceptible of manipulation at a distance. The insulator of theinvention has the advantage that the fixed channel-shaped grippingelement transmits to the cement which holds the stem a substantial partof the stress imposed on the insulator by the conductor. This permitsuse of a smaller stem, and the gripping elements themselves can besmaller as well, while effecting nevertheless a secure support for theconductor and permitting easy assembly and disassembly of the conductorto the insulator.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be furtherdescribed in terms of a presently preferred exemplary embodiment thereofand with reference to the accompanying drawings in which:

FIG. 1 is an axial sectional view of one form of insulator according tothe invention;

FIG. 2 is a view in elevation of that one of the conductor grippingelements in the insulator of FIG. 1 which is fixed with respect to thedielectric elements of the insulator;

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2, shownhowever at an enlarged scale, and with a showing in phantom of theoutermost dielectric element of the insulator and showing in addition,in phantom, lugs or feet which may be included on the gripping elementof FIG. 2 to center it in the cavity of the outermost dielectric elementof the insulator; and

FIG. 4 is a view in side elevation of the movable conductor grippingelement in the insulator of FIG. 1.

The insulator of FIG. 1 is of the horizontal type. It comprises twodielectric elements 1 and 2, typically of glass or porcelain, joinedtogether by a metallic sleeve 3 which is sealed to those elements bymeans of a cement 4. Each of the elements 1 and 2 includes a crown 22and a skirt 23, the skirt of element 1 surrounding a cavity 5 thereinand the skirt of element 2 surrounding a cavity 19 therein. The element1 includes a cavity 5 at which it is sealed to a pin 15, again by meansof cement as indicated at 16, for support of the insulator on a post Inaccordance with the invention the conductor 7, supported by the outerdielectric element 2, is gripped between two gripping elements 8 and 9which include channel-shaped portions 8a and 9a (FIGS. 3 and 4) forengagement with the conductor. The gripping elements 8 and 9 are eachapertured, as indicated at 17 in FIG. 2 for the element 8 and at 20 inFIG. 4 for the element 9, to pass over a threaded rod or stem 10, sealedby means of cement 18 into a cavity 19 of the outer dielectric element2. The gripping element 9 is movable on the stem 10, whereas thegripping element 8 is fixed with respect thereto and with respect to theouter dielectric element 2 by means of the cement 18. The grippingelement 8 may be provided with roughening on the convex surface thereof,to assist its adhesion to the cement 18. A nut 11, threaded onto the rod10 makes it possible to clamp the conductor between the grippingelements 8 and 9. The nut may include a clevis-like bridle or loop 21 tofacilitate remote manipulation of the nut. Notches not visible in thesectional view of FIG. 1 are provided in the dielectric element 2 toaccommodate the conductor 7.

As hereinabove indicated, a large part of the stress carried by theelements 8 and 9 is transmitted to the body of cement 18 contained inthe cavity 19 of the dielectric element 2. More particularly, a part atleast of the stress imposed by the conductor 7 onto the element 8 istransmitted directly by the latter to the body of cement l8 and thenceto the dielectric element 2, and is not borne by the stem 10. The stem10 can consequently be of small cross-section and the elements 8 and 9may themselves be of light construction, being made for example simplyof galvanized sheet iron. The cement employed at 4, 16 and 18 isdesirably a fibrous cement.

To center the fixed gripping element 8 with respect to the stem 10 anddielectric element 2, and additionally to assist independently of thestem 10 transfer to the dielectric element 2 of the stress imposed onthe insulator by the conductor 7, the fixed gripping element 8 may beprovided with extensions or lugs as indicated in phantom at 14 in FIG.3, bearing against the inside walls of the cavity 19.

It will be observed that the dielectric element 1 does not rest directlyagainst the post 6. Rather, a collar 13 of plastic material or the likeavoids direct contact between the post and the element 1. Thisarrangement limits the bending stress to which the pin 15 is subjectedby the conductor. Lugs may be provided on the collar 13 to fit withinthe cavity 5 and thereby to center the collar with respect to thedielectric element 1, and to facilitate sealing of the collar to thatdielectric element.

The stem may be offset from the axis of the element 2 so as to disposethe conductor 7 on the axial plane of the insulator.

It will thus be seen that the invention provides a pintype insulatorcomprising a plurality of dielectric. elements as indicated at l and 2of the drawings, for example, and means such as the cement 4 supportingthose elements in a linear array and in fixed relative position. Thearray need not however be straight. The insulator further comprises atleast two channel-shaped conductor gripping elements, such astheelements 8 and 9, and means such as the cement 18 sealing one of thosegripping elements to the dielectric element at one end of the array. Theinsulator further comprises two-part interengaging means such as thestem 10 and the nut 11 to stress the two gripping elements together. Theinsulator may further comprise a pin as indicated at at the end of thearray opposite that of the conductor gripping means, and a collar orwasher as indicated at 13 engaged on that pin.

While the application has been described hereinabove in terms of apresently preferred exemplary embodiment, the invention itself is notlimited thereto but rather comprehends all modifications of anddepartures from that embodiment falling within the scope of the appendedclaims.

I claim:

1. A horizontal pin-type insulator comprising a metallic sleeve, twocup-shaped dielectric elements having each a crown and having each askirt surrounding a cavity, said elements being coaxially disposed withtheir crowns adjacent each other inside said sleeve, a first mass ofcementitious material filling said sleeve and holding said elements andsleeve in fixed coaxial relation, a stem cemented into the cavity of oneof said elements for affixation of the insulator to a support, a secondmass of cementitious material in the cavity of the other of saidelements, at least two complementary conductor gripping elements shapedto em brace opposite sides of a filamentary conductor, one of saidgripping elements being sealed in said second mass of cementitiousmaterial, and two-part interengaging means carried by said otherdielectric element to stress the other of said gripping elements againstsaid one gripping element.

2. A pin-type insulator according to claim 1 wherein said one grippingelement comprises a channel embedded in said second mass of cementitiousmaterial.

3. A pin-type insulator according to claim 2 wherein said one grippingelement further comprises extensions bearing against the inside walls ofthe cavity in said other dielectric element.

4. A pin-type insulator according to claim 1 wherein said interengagingmeans comprise a threaded stem embedded in said second mass ofcementitious material and a nut engaged on said last-named stem.

1. A horizontal pin-type insulator comprising a metallic sleeve, twocup-shaped dielectric elements having each a crown and having each askirt surrounding a cavity, said elements being coaxially disposed withtheir crowns adjacent each other inside said sleeve, a first mass ofcementitious material filling said sleeve and holding said elements andsleeve in fixed coaxial relation, a stem cemented into the cavity of oneof said elements for affixation of the insulator to a support, a secondmass of cementitious material in the cavity of the other of saidelements, at least two complementary conductor gripping elements shapedto embrace opposite sides of a filamentary conductor, one of saidgripping elements being sealed in said second mass of cementitiousmaterial, and two-part interengaging means carried by said otherdielectric element to stress the other of said gripping elements againstsaid one gripping element.
 1. A horizontal pin-type insulator comprisinga metallic sleeve, two cup-shaped dielectric elements having each acrown and having each a skirt surrounding a cavity, said elements beingcoaxially disposed with their crowns adjacent each other inside saidsleeve, a first mass of cementitious material filling said sleeve andholding said elements and sleeve in fixed coaxial relation, a stemcemented into the cavity of one of said elements for affixation of theinsulator to a support, a second mass of cementitious material in thecavity of the other of said elements, at least two complementaryconductor gripping elements shaped to embrace opposite sides of afilamentary conductor, one of said gripping elements being sealed insaid second mass of cementitious material, and two-part interengagingmeans carried by said other dielectric element to stress the other ofsaid gripping elements against said one gripping element.
 2. A pin-typeinsulator according to claim 1 wherein said one gripping elementcomprises a channel embedded in said second mass of cementitiousmaterial.
 3. A pin-type insulator according to claim 2 wherein said onegripping element further comprises extensions bearing against the insidewalls of the cavity in said other dielectric element.